Patois (/ˈpætwɑː/, pl. same or /ˈpætwɑːz/) is speech or language that is considered nonstandard, although the term is not formally defined in linguistics. As such, patois can refer to pidgins, creoles, dialects, or vernaculars, but not commonly to jargon or slang, which are vocabulary-based forms of cant.
Class distinctions are implied in the term, as patois in French refers to a sociolect associated with uneducated rural classes and is contrasted with the dominant prestige language as used in literature and formal settings (the ‘acrolect’).
The term patois comes from Old French, patois “local or regional dialect” (earlier “rough, clumsy, or uncultivated speech”), possibly from the verb patoier, “to treat roughly”, from pate “paw”, from Old Low Franconian *patta paw, “sole of the foot” + -ois, a pejorative suffix. The language sense may have arisen from the notion of a clumsy or rough manner of speaking.